Peptide Receptor Radionuclide Therapy in Patients with Advanced Progressive Medullary Thyroid Cancer: Efficacy, Safety and Survival Predictors

Ziel/Aim Metastatic medullary thyroid carcinoma (MTC) is often has a rapid disease progression and poor prognosis with few therapeutic options available. Peptide Receptor Radionuclide Therapy (PRRT) has demonstrated success in the management of gastroenteropancreatic neuroendocrine tumors and has also been used to treat MTC. The objective of this study was to assess the safety and efficacy of PRRT in patients with advanced, progressive MTC, to determine survival and potential predictors of survival.

Methodik/Methods From September 2003 to June 2019, 28 patients (15 men, 13 women; mean age, 49±14 y) with progressive, somatostatin receptor-positive MTC received PRRT with ¹⁷⁷Lu- or ⁹⁰Y- labeled somatostatin analogs at Zentralklinik Bad Berka (ZBB), Germany. Toxicity was graded according to CTCA v.5.0. Treatment response was evaluated by RECIST 1.1 as well as EORTC criteria. Kaplan–Meier analysis was used to calculate progression-free survival (PFS) and overall survival (OS), defined from the start of PRRT. Cox regression analyses were performed to identify parameters associated with PFS and OS.

Ergebnisse/Results Seventy-seven cycles of PRRT were administered (mean cumulative administered activity, 16.0±7.8 GBq). No acute or long-term grade 3/4 toxicity was recorded with a follow-up of 3-140months, except for one (4%) patient who suffered from grade 3 anemia likely related to disease progression. By RECIST criteria, the disease control rate (DCR) after 3-4months of PRRT was 56.0% (partial remission, 12.0%; stable disease, 44.0%). The DCR (72.0%) was higher by EORTC. Median OS and PFS were 63.7 months and 10.1 months. Annual OS rates were 84% at 1 year, 65% at 3 years, 57% at 5 years, and 18% at 10 years. Annual PFS rates were 42% at 1 year, 21% at 2 years, and 13% at 5 years. Patients with bone metastases had poorer OS and PFS than those without metastases (median OS, 58.7 months vs. 92.3 months, P=0.035 [HR, 2.7; 95% CI, 0.92-7.84]; median PFS, 8.5 months vs. 12.8 months, P=0.592 [HR, 1.2; 95% CI, 0.56-2.76]).

Schlussfolgerungen/Conclusions PRRT was well tolerated and effective in patients with advanced, aggressive MTC. Bone metastases was an independent adverse prognostic factor for OS.

Publication History

Article published online:
30 March 2023